2185. Counting Words With a Given Prefix

Problem

You are given an array of strings words and a string pref.

Return **the number of strings in *words* that contain pref as a prefix**.

A prefix of a string s is any leading contiguous substring of s.

  Example 1:

Input: words = ["pay","attention","practice","attend"], pref = "at"
Output: 2
Explanation: The 2 strings that contain "at" as a prefix are: "attention" and "attend".

Example 2:

Input: words = ["leetcode","win","loops","success"], pref = "code"
Output: 0
Explanation: There are no strings that contain "code" as a prefix.

  Constraints:

• 1 <= words.length <= 100

• 1 <= words[i].length, pref.length <= 100

• words[i] and pref consist of lowercase English letters.

Solution (Java)

class Solution {
    public int prefixCount(String[] words, String pref) {
        int count = 0;
        for (String s : words) {
            if (s.startsWith(pref)) {
                count++;
            }
        }
        return count;
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).